基于NUMISHEET 2002会议提出的杯形件拉深Benchmark试验方案,在5和30 k N两种压边力工况下,对2 mm厚2024铝合金板料的拉深性能、凸耳现象、回弹现象及板厚变化进行试验研究,采用DYNAFORM软件对拉深过程进行有限元仿真。试验和仿真结果...基于NUMISHEET 2002会议提出的杯形件拉深Benchmark试验方案,在5和30 k N两种压边力工况下,对2 mm厚2024铝合金板料的拉深性能、凸耳现象、回弹现象及板厚变化进行试验研究,采用DYNAFORM软件对拉深过程进行有限元仿真。试验和仿真结果比较表明,在两种不同压边力工况下,2024铝合金具有较好的拉深性能,拉深件均出现凸耳、回弹及板料厚度变化不均等现象。在与板料轧制方向成0°、90°、180°和270°产生了4个凸耳;在低压边力工况下,与板料轧制方向垂直方向回弹量最大,为3.14%;随着凸模行程的增加,拉深力增大,当凸模行程为26 mm时,拉深力呈平缓趋势。展开更多
试验研究了用于航空结构的三维整体编织复合材料单耳承力接头在静载条件下的承载能力与破坏模式。单耳接头试样采用RTM(Resin Transfer Molding树脂传递模塑)工艺制成,重点研究了由3种编织工艺(三维四向、三维五向和三维六向)、2种连接...试验研究了用于航空结构的三维整体编织复合材料单耳承力接头在静载条件下的承载能力与破坏模式。单耳接头试样采用RTM(Resin Transfer Molding树脂传递模塑)工艺制成,重点研究了由3种编织工艺(三维四向、三维五向和三维六向)、2种连接孔加工方式(机械钻孔和编织孔)、2种几何外形所组成的10组三维编织复合材料单耳承力接头的破坏机理与破坏载荷。对其在航空结构中的可应用性做出了评估。展开更多
Networked customization had gradually become one of t he import manufacturing and marketing patterns in the information age. Product d escription had an important effect on realizing networked customization. From th i...Networked customization had gradually become one of t he import manufacturing and marketing patterns in the information age. Product d escription had an important effect on realizing networked customization. From th is point of view, this paper firstly analyzed four requirements of adaptability, stability, conciseness and definitude that product description methods for netw orked customization must satisfy. According to these requirements, the paper com mented on current methods of product description, pointing out their advantages and disadvantages. As none of current methods could satisfy the four requirement s simultaneously, they were not fully applicable to networked customization. The n a plug-in based product description method was brought forward and discussed in detail. In this method, product description for networked customization w as abstracted as three component parts of basic description, basic feature and c ustomization feature. These parts had different characteristics. Basic descripti on was applicable to all products types. Basic feature was stable as concerning specific product type. Variants of certain product type all possessed identi cal basic features. Customization features were variable. Different combinations of customization features would give birth to different product variants. Apply ing object-oriented method, three standard product description plug-ins could be got by encapsulating these component parts. As "basic feature" and "customiza tion feature" plug-in had similar structures, they could be further abstracted as "feature" plug-in. When describing a type of product, a "basic description" plug-in would be instantiated firstly. Then according to product’s specific ch aracteristics, necessary number of "basic feature" and "customization feature" p lug-ins would be instantiated and appended, such as "color", "material", etc. E ach "basic feature" plug-in related to an instantiated "feature value" plug-in , while each "customization feature" plug-in related to one or multiple in展开更多
通过单向拉伸试验研究了三维多向整体编织复合材料单耳承力接头的破坏模式。试样选用T700碳纤维和环氧树脂,采用RTM(resin transfer molding树脂传递模塑)工艺制成。试验针对由3种编织工艺(三维四向编织、三维五向编织和三维六向编织)...通过单向拉伸试验研究了三维多向整体编织复合材料单耳承力接头的破坏模式。试样选用T700碳纤维和环氧树脂,采用RTM(resin transfer molding树脂传递模塑)工艺制成。试验针对由3种编织工艺(三维四向编织、三维五向编织和三维六向编织)、两种连接孔加工方式(机械钻孔和编织孔)、两种几何外形所组成的十组三维编织复合材料单耳承力接头的破坏机理与破坏载荷进行了初步探索研究,并对其在航空结构中的可应用性做出了评估。展开更多
Lug joints are preferred joineries for transferring heavy loads to parent components in aerospace vehicles.They experience corrosion due to environmental conditions,improper surface finishes and rubbing displacement b...Lug joints are preferred joineries for transferring heavy loads to parent components in aerospace vehicles.They experience corrosion due to environmental conditions,improper surface finishes and rubbing displacement between the pin and lug-hole.This causes damage of different sizes and shapes near the lug-hole.Stiffness degradation due to corrosion-induced damage is modelled as a through-pit at one of the identified critical locations through stress analysis.The effect of this pit on fatigue crack initiation life is estimated.Lug-hole is pre-stressed by cold-working and the benefits of inducing plastic wake on the intended performance of the lug joint during the damages due to corrosion are brought out and compared with non-cold-worked lug-hole.Numerical analysis is performed on this lug joint with pressfit.The results obtained highlight the benefits of cold-working and the methodology can be extended to damage growth and analyse the effect of surface treatments for better structural integrity of components of aerospace vehicles.展开更多
文摘试验研究了用于航空结构的三维整体编织复合材料单耳承力接头在静载条件下的承载能力与破坏模式。单耳接头试样采用RTM(Resin Transfer Molding树脂传递模塑)工艺制成,重点研究了由3种编织工艺(三维四向、三维五向和三维六向)、2种连接孔加工方式(机械钻孔和编织孔)、2种几何外形所组成的10组三维编织复合材料单耳承力接头的破坏机理与破坏载荷。对其在航空结构中的可应用性做出了评估。
文摘Networked customization had gradually become one of t he import manufacturing and marketing patterns in the information age. Product d escription had an important effect on realizing networked customization. From th is point of view, this paper firstly analyzed four requirements of adaptability, stability, conciseness and definitude that product description methods for netw orked customization must satisfy. According to these requirements, the paper com mented on current methods of product description, pointing out their advantages and disadvantages. As none of current methods could satisfy the four requirement s simultaneously, they were not fully applicable to networked customization. The n a plug-in based product description method was brought forward and discussed in detail. In this method, product description for networked customization w as abstracted as three component parts of basic description, basic feature and c ustomization feature. These parts had different characteristics. Basic descripti on was applicable to all products types. Basic feature was stable as concerning specific product type. Variants of certain product type all possessed identi cal basic features. Customization features were variable. Different combinations of customization features would give birth to different product variants. Apply ing object-oriented method, three standard product description plug-ins could be got by encapsulating these component parts. As "basic feature" and "customiza tion feature" plug-in had similar structures, they could be further abstracted as "feature" plug-in. When describing a type of product, a "basic description" plug-in would be instantiated firstly. Then according to product’s specific ch aracteristics, necessary number of "basic feature" and "customization feature" p lug-ins would be instantiated and appended, such as "color", "material", etc. E ach "basic feature" plug-in related to an instantiated "feature value" plug-in , while each "customization feature" plug-in related to one or multiple in
文摘通过单向拉伸试验研究了三维多向整体编织复合材料单耳承力接头的破坏模式。试样选用T700碳纤维和环氧树脂,采用RTM(resin transfer molding树脂传递模塑)工艺制成。试验针对由3种编织工艺(三维四向编织、三维五向编织和三维六向编织)、两种连接孔加工方式(机械钻孔和编织孔)、两种几何外形所组成的十组三维编织复合材料单耳承力接头的破坏机理与破坏载荷进行了初步探索研究,并对其在航空结构中的可应用性做出了评估。
文摘Lug joints are preferred joineries for transferring heavy loads to parent components in aerospace vehicles.They experience corrosion due to environmental conditions,improper surface finishes and rubbing displacement between the pin and lug-hole.This causes damage of different sizes and shapes near the lug-hole.Stiffness degradation due to corrosion-induced damage is modelled as a through-pit at one of the identified critical locations through stress analysis.The effect of this pit on fatigue crack initiation life is estimated.Lug-hole is pre-stressed by cold-working and the benefits of inducing plastic wake on the intended performance of the lug joint during the damages due to corrosion are brought out and compared with non-cold-worked lug-hole.Numerical analysis is performed on this lug joint with pressfit.The results obtained highlight the benefits of cold-working and the methodology can be extended to damage growth and analyse the effect of surface treatments for better structural integrity of components of aerospace vehicles.
